Manual: nsenter
NSENTER(1) User Commands NSENTER(1)
NAME
nsenter - run program in different namespaces
SYNOPSIS
nsenter [options] [program [arguments]]
DESCRIPTION
The nsenter command executes program in the namespace(s) that are specified in the command-line options (described
below). If program is not given, then "${SHELL}" is run (default: /bin/sh).
Enterable namespaces are:
mount namespace
Mounting and unmounting filesystems will not affect the rest of the system, except for filesystems which are
explicitly marked as shared (with mount --make-shared; see /proc/self/mountinfo for the shared flag). For further
details, see mount_namespaces(7) and the discussion of the CLONE_NEWNS flag in clone(2).
UTS namespace
Setting hostname or domainname will not affect the rest of the system. For further details, see
uts_namespaces(7).
IPC namespace
The process will have an independent namespace for POSIX message queues as well as System V message queues,
semaphore sets and shared memory segments. For further details, see ipc_namespaces(7).
network namespace
The process will have independent IPv4 and IPv6 stacks, IP routing tables, firewall rules, the /proc/net and
/sys/class/net directory trees, sockets, etc. For further details, see network_namespaces(7).
PID namespace
Children will have a set of PID to process mappings separate from the nsenter process. nsenter will fork by
default if changing the PID namespace, so that the new program and its children share the same PID namespace and
are visible to each other. If --no-fork is used, the new program will be execâed without forking. For further
details, see pid_namespaces(7).
user namespace
The process will have a distinct set of UIDs, GIDs and capabilities. For further details, see user_namespaces(7).
cgroup namespace
The process will have a virtualized view of /proc/self/cgroup, and new cgroup mounts will be rooted at the
namespace cgroup root. For further details, see cgroup_namespaces(7).
time namespace
The process can have a distinct view of CLOCK_MONOTONIC and/or CLOCK_BOOTTIME which can be changed using
/proc/self/timens_offsets. For further details, see time_namespaces(7).
OPTIONS
Various of the options below that relate to namespaces take an optional file argument. This should be one of the
/proc/[pid]/ns/* files described in namespaces(7), or the pathname of a bind mount that was created on one of those
files.
-a, --all
Enter all namespaces of the target process by the default /proc/[pid]/ns/* namespace paths. The default paths to
the target process namespaces may be overwritten by namespace specific options (e.g., --all --mount=[path]).
The user namespace will be ignored if the same as the callerâs current user namespace. It prevents a caller that
has dropped capabilities from regaining those capabilities via a call to setns(). See setns(2) for more details.
-t, --target PID
Specify a target process to get contexts from. The paths to the contexts specified by pid are:
/proc/pid/ns/mnt
the mount namespace
/proc/pid/ns/uts
the UTS namespace
/proc/pid/ns/ipc
the IPC namespace
/proc/pid/ns/net
the network namespace
/proc/pid/ns/pid
the PID namespace
/proc/pid/ns/user
the user namespace
/proc/pid/ns/cgroup
the cgroup namespace
/proc/pid/ns/time
the time namespace
/proc/pid/root
the root directory
/proc/pid/cwd
the working directory respectively
-m, --mount[=file]
Enter the mount namespace. If no file is specified, enter the mount namespace of the target process. If file is
specified, enter the mount namespace specified by file.
-u, --uts[=file]
Enter the UTS namespace. If no file is specified, enter the UTS namespace of the target process. If file is
specified, enter the UTS namespace specified by file.
-i, --ipc[=file]
Enter the IPC namespace. If no file is specified, enter the IPC namespace of the target process. If file is
specified, enter the IPC namespace specified by file.
-n, --net[=file]
Enter the network namespace. If no file is specified, enter the network namespace of the target process. If file
is specified, enter the network namespace specified by file.
-N, --net-socket fd
Enter the network namespace of the target processâs socket. It requires --target process specified. Supported
since Linux 5.6.
-p, --pid[=file]
Enter the PID namespace. If no file is specified, enter the PID namespace of the target process. If file is
specified, enter the PID namespace specified by file.
-U, --user[=file]
Enter the user namespace. If no file is specified, enter the user namespace of the target process. If file is
specified, enter the user namespace specified by file. See also the --setuid and --setgid options.
--user-parent
Enter the parent user namespace. Parent user namespace will be acquired from any other enabled namespace. If
combined with --user option the parent user namespace will be fetched from the user namespace and replace it.
-C, --cgroup[=file]
Enter the cgroup namespace. If no file is specified, enter the cgroup namespace of the target process. If file is
specified, enter the cgroup namespace specified by file.
-T, --time[=file]
Enter the time namespace. If no file is specified, enter the time namespace of the target process. If file is
specified, enter the time namespace specified by file.
-G, --setgid gid
Set the group ID which will be used in the entered namespace and drop supplementary groups. nsenter always sets
GID for user namespaces, the default is 0. If the argument "follow" is specified the GID of the target process is
used.
-S, --setuid uid
Set the user ID which will be used in the entered namespace. nsenter always sets UID for user namespaces, the
default is 0. If the argument "follow" is specified the UID of the target process is used.
--keep-caps
When the --user option is given, ensure that capabilities granted in the user namespace are preserved in the
child process.
--preserve-credentials
Donât modify UID and GID when enter user namespace. The default is to drops supplementary groups and sets GID and
UID to 0.
-r, --root[=directory]
Set the root directory. If no directory is specified, set the root directory to the root directory of the target
process. If directory is specified, set the root directory to the specified directory. The specified directory is
open before it switches to the requested namespaces.
-w, --wd[=directory]
Set the working directory. If no directory is specified, set the working directory to the working directory of
the target process. If directory is specified, set the working directory to the specified directory. The
specified directory is open before it switches to the requested namespaces, it means the specified directory
works as "tunnel" to the current namespace. See also --wdns.
-W, --wdns[=directory]
Set the working directory. The directory is open after switch to the requested namespaces and after chroot(2)
call. The options --wd and --wdns are mutually exclusive.
-e, --env
Pass environment variables from the target process to the new process being created. If this option is not
provided, the environment variables will remain the same as in the current namespace..
-F, --no-fork
Do not fork before execâing the specified program. By default, when entering a PID namespace, nsenter calls fork
before calling exec so that any children will also be in the newly entered PID namespace.
-Z, --follow-context
Set the SELinux security context used for executing a new process according to already running process specified
by --target PID. (The util-linux has to be compiled with SELinux support otherwise the option is unavailable.)
-c, --join-cgroup
Add the initiated process to the cgroup of the target process.
-h, --help
Display help text and exit.
-V, --version
Display version and exit.
NOTES
The --user-parent option requires Linux 4.9 or higher, older kernels will raise inappropriate ioctl for device error.
AUTHORS
Eric Biederman , Karel Zak
SEE ALSO
clone(2), setns(2), namespaces(7)
REPORTING BUGS
For bug reports, use the issue tracker .
AVAILABILITY
The nsenter command is part of the util-linux package which can be downloaded from Linux Kernel Archive
.
util-linux 2.41.3 2025-12-15 NSENTER(1)